The Human Rights Watch (HRW) has said that eyewitness accounts and evidence gathered from Syria's northwestern Idlib province "strongly" suggested that the regime used chemical weapons on civilians several times last month.
The New York-based group said that the chemicals appeared to have been packed into crude explosives-filled barrels and airdropped on areas held by rebels during heavy fighting between March 16 and 31, 2015 in Idlib, reported News24.
It also urged the United Nations Security Council to probe the allegations which would be a breach of both its own resolutions and Damascus's obligations under the Chemical Weapons Convention.
The claims were however, rejected by a senior Syrian security official who said that the accusations were lies concocted by insurgents when they incurred losses.
The monitoring group's report came as at least 12 people were killed in a barrel bomb attack in the province on Tuesday.